ᐅ Photovoltaic system in a new build: Would you install one? Any experiences?
Created on: 27 May 2018 10:44
S
Skyfire
Hello everyone,
I am in the final stages of planning my house.
Here are the key details of the building:
- Location: Low mountain range
- House: Timber frame
KFW 55 --> Qp = 40.9 kWh/m² and H′T = 0.259 W/(m²K)
Thermal bridge loss = 0.038 W/(m²K)
Usable roof area: approx. 40 m² (430 sq ft)
- Roof pitch: 35 degrees gable roof
- Orientation: Southeast
- Roof window: 1 centered
- Heated building volume: 497.9 m³ (17,580 cu ft)
- Usable floor area: 159.3 m² (1,714 sq ft)
The heating system will be an air-to-water heat pump and a central controlled mechanical ventilation system with heat recovery.
At the moment, I am considering the possibility of installing a photovoltaic system.
Putting ecological considerations aside and focusing purely on economic factors, is a photovoltaic system worth it in the long term? Does it make sense to try to reduce heating and electricity costs with such a system?
I think the payback time will be quite long, and it provides the least output in winter when the heat pump consumes the most energy.
What are your thoughts on installing such a system? Would you build one?
Thank you very much.
Best regards,
Steffen
I am in the final stages of planning my house.
Here are the key details of the building:
- Location: Low mountain range
- House: Timber frame
KFW 55 --> Qp = 40.9 kWh/m² and H′T = 0.259 W/(m²K)
Thermal bridge loss = 0.038 W/(m²K)
Usable roof area: approx. 40 m² (430 sq ft)
- Roof pitch: 35 degrees gable roof
- Orientation: Southeast
- Roof window: 1 centered
- Heated building volume: 497.9 m³ (17,580 cu ft)
- Usable floor area: 159.3 m² (1,714 sq ft)
The heating system will be an air-to-water heat pump and a central controlled mechanical ventilation system with heat recovery.
At the moment, I am considering the possibility of installing a photovoltaic system.
Putting ecological considerations aside and focusing purely on economic factors, is a photovoltaic system worth it in the long term? Does it make sense to try to reduce heating and electricity costs with such a system?
I think the payback time will be quite long, and it provides the least output in winter when the heat pump consumes the most energy.
What are your thoughts on installing such a system? Would you build one?
Thank you very much.
Best regards,
Steffen
H
hampshire17 Jun 2018 19:57Technical differences:
The output per area is about 100 Wp/m² (9.3 Wp/sq ft), which is lower than top panels because the coverage area with monocrystalline photovoltaic cells per square meter is smaller.
The system operates at low voltage – therefore, in case of fire, the house can be extinguished safely.
The system, consisting of many small individual modules, is less sensitive to shading (which is not an issue in our case).
The technology of control via inverter to storage is not dependent on the type of photovoltaic panels, so I do not see any technical difference there.
Technically, I cannot identify one as “worse” as long as there is enough roof area. I consider the “more expensive” option as an investment in the appearance of the house – similar to wooden cladding or a special paint finish.
The output per area is about 100 Wp/m² (9.3 Wp/sq ft), which is lower than top panels because the coverage area with monocrystalline photovoltaic cells per square meter is smaller.
The system operates at low voltage – therefore, in case of fire, the house can be extinguished safely.
The system, consisting of many small individual modules, is less sensitive to shading (which is not an issue in our case).
The technology of control via inverter to storage is not dependent on the type of photovoltaic panels, so I do not see any technical difference there.
Technically, I cannot identify one as “worse” as long as there is enough roof area. I consider the “more expensive” option as an investment in the appearance of the house – similar to wooden cladding or a special paint finish.
Poor performance due to lack of ventilation = lower efficiency.
In general, in-roof solutions are still quite rare and usually come at premium prices.
I would still really, really like to see a picture of that
(Aesthetics are not an argument for me; all-black modules on a properly sized roof look very good in my opinion. I myself have a flat roof, so it doesn’t really matter there)
In general, in-roof solutions are still quite rare and usually come at premium prices.
I would still really, really like to see a picture of that
(Aesthetics are not an argument for me; all-black modules on a properly sized roof look very good in my opinion. I myself have a flat roof, so it doesn’t really matter there)
You don’t have to defend that. You have set your priorities and made your decision accordingly. That’s perfectly fine, and they really do look good.
As you can see here in the forum alone, the question of investment usually revolves first around payback and profit. With a system like this, that’s rather “difficult.”
As you can see here in the forum alone, the question of investment usually revolves first around payback and profit. With a system like this, that’s rather “difficult.”
H
hampshire17 Jun 2018 20:14Yes, that simply takes longer.
D
daniels8717 Jun 2018 21:42Alex85 schrieb:
The profit often comes down to purchasing.
Everyone and their dog offers photovoltaic systems on the side. The prices are accordingly very low.
For us, it went from 2000€/kWp (heating installer with a "complete solution from Vaillant") to 1700€/kWp from the electrician, 1600€/kWp (solar specialist; high-quality components but still too expensive), now down to 1150€/kWp (regional solar specialist with solid components). All prices are all-inclusive, net, without storage (of course).
If you want it to pay off financially, you have to buy cheaply and especially forego a storage solution, unless it might be worthwhile due to already existing costs and subsidies. Then a 5% return is quite possible in my opinion.How many kWp did you have installed? And can you share the name of your regional solar specialist? Feel free to send me a private message. Thanks!
I have also been considering installing photovoltaic modules on the still-planned carport to save on the wooden roof and the EPDM membrane. That, plus self-installation, increases profitability.
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